NeXJ
NAXJA Forum User
- Location
- Los Angeles
I'm trying to get my 92 XJ back on the road after having sat for about a year and a half since it failed smog last time (that's partly why it's been sitting so long!). Last year's fail was supposedly due to a dead cylinder, which has now been repaired.
At any rate - last year I replaced all the plugs, wires, new rotor and cap, all the usual stuff - including a new TPS since the last one died, new aftermarket O2 sensor if I recall correctly. At the time, only the NOx was high.
Before I go on - I SHOULD mention that YES - I've read some of the other smog posts so I'm familiar to some degree with the issues - but this seemed a weird case - so I thought I should post it.
Today - I did another smog and got the following results:
15MPH %CO2=14.2 %O2=0.0 HC=131 (max=86) CO=1.02 (max=0.51) NO=1245 (max=711)
25MPH %CO2=14.5 %O2=0.0 HC=102 (max=72) CO=.85 (max=0.65) NO=892 (max=613)
The smog guy told me that it was probably largely due to buying the 'aftermarket' O2 sensor - and that the OEM sensor should give me improved results and that I should get a new coolant temp sensor as well, and change out the custom headers, cat and exhaust (though I passed with those four years ago when I did it last), among other things. IF I choose to get the new O2 sensor - my conundrum is whether I should get the 92 version or the 97 version. The computers are different. It seems (maybe) I should get the 92 since my computer is a 92 (?).
But a likely culprit, it seems to me, might be that I did the test on the residual (less than a gallon) of gas that was 1.5 years old (???). I'm not sure if I did the oil change last time.
92 XJ Sport with 1998 HO 4.0L
Borla Headers high flow everything (incl cat, exhaust etc etc)
IDEAS??? SUGGESTIONS???
I thought maybe if I change out the oil and the gas and or run something special in the gas (alcohol or acetone) I might get the numbers down...(??)
At any rate - last year I replaced all the plugs, wires, new rotor and cap, all the usual stuff - including a new TPS since the last one died, new aftermarket O2 sensor if I recall correctly. At the time, only the NOx was high.
Before I go on - I SHOULD mention that YES - I've read some of the other smog posts so I'm familiar to some degree with the issues - but this seemed a weird case - so I thought I should post it.
Today - I did another smog and got the following results:
15MPH %CO2=14.2 %O2=0.0 HC=131 (max=86) CO=1.02 (max=0.51) NO=1245 (max=711)
25MPH %CO2=14.5 %O2=0.0 HC=102 (max=72) CO=.85 (max=0.65) NO=892 (max=613)
The smog guy told me that it was probably largely due to buying the 'aftermarket' O2 sensor - and that the OEM sensor should give me improved results and that I should get a new coolant temp sensor as well, and change out the custom headers, cat and exhaust (though I passed with those four years ago when I did it last), among other things. IF I choose to get the new O2 sensor - my conundrum is whether I should get the 92 version or the 97 version. The computers are different. It seems (maybe) I should get the 92 since my computer is a 92 (?).
But a likely culprit, it seems to me, might be that I did the test on the residual (less than a gallon) of gas that was 1.5 years old (???). I'm not sure if I did the oil change last time.
92 XJ Sport with 1998 HO 4.0L
Borla Headers high flow everything (incl cat, exhaust etc etc)
IDEAS??? SUGGESTIONS???
I thought maybe if I change out the oil and the gas and or run something special in the gas (alcohol or acetone) I might get the numbers down...(??)